The present invention relates generally to roller window shades and, more particularly, relates to a roller shade configured to be repeatedly width adjustable and configured to maintain proper orthogonal tracking of the shade at any available width selected for the window shade.
Roller-type retractable window shades have long been used to provide shade and privacy for the interiors of buildings and automobiles. A multitude of different window widths is a problem that has plagued the designers of these window shades. One approach to solving this problem is to construct a wide range of different fixed-width window shades, such that a different fixed-width window shade is available for every different window width. Of course, this approach to the problem results in a very large inventory of fixed-width shades, and prevents using the same window shade with windows of different width.
To avoid having to construct a different fixed-width shade for each different window width, attempts have been made to construct adjustable-width window shades. In particular, xe2x80x9ccut-to-fitxe2x80x9d window shades have been constructed that permit easy width modification at the site of installation. However, once cut to a desired size, these window shades can no longer be expanded to their original maximum width. Thus, these configurations only provide a partial solution to the problem. In particular, these xe2x80x9ccut-to-fitxe2x80x9d window shades are not truly xe2x80x9cadjustable-widthxe2x80x9d in that they are not repeatedly width-adjustable within their original range of width adjustment. Moreover, adjustable-width roller shades, which are specifically configured for deployment in automobiles, are not commercially available at present.
It is believed that the present unavailability of truly adjustable-width widow shades results from the inability of roller shade designers to solve the problem of mounting overlapping shade sheets on a roller that telescopes to provide width adjustment. A second unsolved problem is to design a telescoping shade that maintains xe2x80x9cproper orthogonal trackingxe2x80x9d at all available widths within the shade""s range of width adjustment. Generally, xe2x80x9cproper orthogonal trackingxe2x80x9d is the ability of the shade to remain sufficiently perpendicular to the roller, as the shade winds onto the roller, to prevent an unacceptable amount of movement of the shade along the roller. In other words, proper orthogonal tracking allows the shade to wind on top of itself as it winds onto the roller, in order to prevent the shade from traveling along the length of the roller, as the shade repetitively wraps around the roller. In general, partial overlapping of the shade material being wound around the roller results in a varying thickness of the shade material along the length of the roller, prevents proper orthogonal tracking and causes the shade to move along the roller with subsequent turns of the shade around the roller. When this occurs, the window shade may form a cone rather than a cylinder as it winds, and thus bind or become damaged during retraction.
Accordingly, a need exists in the art for an improved adjustable-width window shade that is repeatedly width-adjustable within its original range of width adjustment. There is a further need for an adjustable-width roller shade that is specifically configured for deployment in automobiles. And there is a further need for an adjustable-width roller shade that maintains proper orthogonal tracking within the shade""s range of width adjustment.
The present invention meets the needs described above in an adjustable-width roller shade that maintains proper orthogonal tracking at all available widths within the shade""s range of width adjustment. More particularly, the adjustable-width roller shade utilizes two overlapping window shades and a telescoping roller to provide a shade that is repeatedly width-adjustable within its original range of width adjustment. To keep the shade sufficiently perpendicular to the roller as the shade winds onto the roller, orthogonal tracking spacers, such as strips of pliable material attached to non-overlapped portions of the shade material, compensate for the extra layers existing at the overlapped portion of the shades. Thus, the roller shade maintains proper orthogonal tracking of the shade at all available widths within the shade""s range of width adjustment.
This configuration of the window shade allows the same shade to be adjusted to fit many different windows without having to cut or otherwise permanently alter the window shade. For this reason, multiple window shades may be adjusted, as desired, and placed side-by-side to fit curving and odd-shaped windows, such as automobile windshields and rear windows. Of course, the same roller shade may be used for side windows as well. Thus, the same window shade may be easily and cost effectively deployed to fit most of the windows of every different automobile make and model on the road, without having to cut or otherwise permanently alter the window shades. It is expected that this advantage will result in a far greater deployment of automobiles window shades than prior window shades have been able to accomplish.
In addition, the outer facing surfaces of the window shades provide advertising space that is visible to the public when the shades are pulled down inside parked automobiles. Thus, making the window shades more attractive to a substantial portion of automobile owners has the associated benefit of deploying millions of square feet of advertising space. Accordingly, automobiles including these window shades, with and without advertising indicia printed on the outward facing surfaces of the shades, are considered to be within the scope of the present invention.
Generally described, the present invention is an adjustable-width roller shade including a telescoping roller assembly having an adjustable width. The telescoping roller assembly is characterized by a shade mounting system that allows free telescoping of the roller assembly. The telescoping roller assembly carries a telescoping shade assembly that varies in width in cooperation with changes in the width of the telescoping roller assembly. The telescoping shade assembly is characterized by two shades with inner portions that overlap each other by an amount that varies with the width of the telescoping shade assembly. In addition, each shade defines an outer portion located away from the overlapped inner portion of the corresponding shade. To provide proper orthogonal tracking of the shades onto the roller, the outer portion of each shade carries an orthogonal tracking spacer, such as a strip of pliable material attached along the edge of the sheet with a thickness selected to compensate for the overlapped condition of the inner portion of the corresponding shade as that shade winds around the roller assembly. The shade also includes a spring motor, which is coupled to the roller assembly that operates to store spring energy as the shades are moved from a rolled-in configuration to a rolled-out configuration. This spring motor also uses stored spring energy to move the shades from the rolled-out configuration to the rolled-in configuration.
The roller shade may also include written indicia carried on at least one of the first and second shades that is available for viewing when the shades are in a substantially rolled-out configuration. In particular, the invention may include an automobile having a front windshield of substantial width and carrying multiple roller shades positioned in side-by-side relation across the width of the front windshield. In addition, the invention may include an automobile having a rear window of substantial width and carrying multiple roller shade positioned in side-by-side relation across the width of the rear window.
More specifically described, the telescoping roller assembly may include an inner roller having an outer longitudinal surface defining a cylinder with a longitudinal ridge extending radially outward from the cylinder. The telescoping roller assembly may also include an outer roller having an outer longitudinal surface defining a cylinder with a longitudinal channel cut through a substantial portion of the longitudinal extent of the outer surface. In addition, the inner roller is concentrically received within the outer roller, with the ridge positioned within the channel, to form a telescoping roller assembly of adjustable width. Typically, the first shade is attached to the ridge of the inner roller, and the second shade is connected to the outer surface of the outer roller.
The roller shade may also include a telescoping outer cover housing the roller assembly and constraining the spring motor from unintended release of stored spring energy. In this case, the first and second shades pass through an opening in the cover as the shades move between a fully rolled-in configuration and a substantially rolled-out configuration.
The roller shade may also include a first rod carried by a free edge of the first shade, a second rod carried by a free edge of the second shade; and a clip for securing the first and second rods together after the roller shade has been adjusted to a desired width. In this case, roller shade may also include a hook coupled to at least one of the first and second shades, typically at the clip, for securing the shades in a substantially rolled-out configuration.
In view of the foregoing, it will be appreciated that the adjustable-width roller shade avoids the drawbacks of conventional roller shades, including those configured for xe2x80x9ccut-to-fitxe2x80x9d width adjustment. The specific techniques and structures employed by the invention to improve over the drawbacks of the prior roller shades and accomplish the advantages described above will become apparent from the following detailed description of the embodiments of the invention and the appended drawings and claims.